According to the author, those who presume that the only human problem is a communication problem ignore a basic fact of life, that is ,
A. different people may have different philosophical, political, or religious beliefs
B. fundamental differences in philosophical, political, or religious beliefs can lead to strong dislikes.
C. eelings of dislike can not be dissolved with the warmth of love and mutual understanding but can be concealed by forms of etiquette
D. All of the above